β-delayed neutron emission in the doubly-magic ¹³²Sn region

This presentation will focus on a recent β-decay spectroscopy measurement performed at the ISOLDE Decay Station (IDS) at CERN. The decay of ¹³⁴In, a nucleus southeast of the ¹³²Sn region, was investigated to further test the statistical model description of spherical delayed neutron emitters with low nuclear level densities [1]. Implementation of state-of-the-art neutron detectors, including the Neutron dEtector with multi-neutron (Xn) Tracking (NEXT), enabled the measurement of energy correlations in two-neutron emission for an r-process nucleus for the first time. This capability made it possible to identify two-neutron-emitting states in the ¹³⁴Sn daughter and the i_13/2 neutron single-particle state in ¹³³Sn, which has been elusive and under scrutiny for over a decade [2-6]. Both the experimental results and the comparison with the theoretical models will be presented. These findings provide crucial information about the nuclear structure in the ¹³²Sn region.

References:

[1] J. Heideman et al.; Phys. Rev. C 108, 024311 (2023)

[2] W. Urban, W. Kurcewicz, A. Nowak, et al; EPJ A 5, 239 (1999)

[3] P. Hoff, P. Baumann, A. Huck; Hyperfine Interactions 129, 141 (2000)

[4] A. Korgul et al.; EPJ A 7, 167 (2000)

[5] K. Jones et al.; Nature 465, 454 (2010)

[6] J. Allmond et al.; Phys. Rev. Lett. 112, 172701 (2014)